Lifting device

ABSTRACT

The specification discloses a device for lifting and transporting an article such as a drum. The device includes a mobile frame (2) an actuating lever (20) upon which are pivotally connected hooks (16) which engageable with the top seam (22), of the drum (1). In use, the mobile frame is wheeled so as to straddle the drum, the lever (20) being rotated whereupon the hooks (16) engage the top seam of the drum. Continued rotation of the lever causes an upward and rearward movement of the hooks so that the drum is maintained in a stable position in the frame and in which the weight of the drum is fully borne by the frame.

This invention relates to a device for lifting articles particularly butnot exclusively articles such as metallic drums of large capacity i.e.of the order of 200 liters.

According to the present invention there is provided a device forlifting an article, said device comprising a mobile frame, a pair ofengagement members which, in use, engage the article to be lifted, andan actuator which is pivotally connected so said frame about a firstaxis, said engagement members being connected to said actuator forpivotal movement relative thereto about a second axis, said actuatorbeing rotatable between first and second positions in which, in thefirst position, said engagement members are at a first level relative tothe frame and said second axis is located at a first lateral positionrelative to said first axis, and, in the second position, saidengagement members are at a second level, vertically higher than saidfirst level, relative to the frame and said second axis is located on asecond lateral position relative to said first axis, said second lateralposition being on the opposite side of said second axis to the saidfirst lateral position, said device including abutment means to restrainmovement of said actuator beyond its second position, and wherein, inuse, an article is supported by said engagement members and the weightthereof tends to rotate said actuator into engagement with said abutmentmeans.

In use of the device the frame is brought up to the article, theengagement members engaged therewith and then the actuator is operatedwhich causes elevation of the engagement members and consequently of thearticle. The lateral shifting of the members functions as an over-centrearrangement so that once the article has been elevated its weight isfully borne by the frame.

The invention will now be further described with reference to theaccompanying drawings, in which:

FIG. 1 is a perspective view of a preferred form of the invention;

FIG. 1A illustrates upward and rearward movement of the hooks;

FIG. 2 illustrates diagrammatically how the apparatus of FIG. 1 can beused to lift a large capacity drum;

FIG. 3 is a plan view of part of the apparatus shown in FIG. 1;

FIG. 4 is a sectional view taken along the line 4--4 marked in FIG. 3;

FIG. 5 is a similar view to FIG. 4 but with the handle rotateddownwardly;

FIG. 6 is a side perspective showing the apparatus lifting a drum, and

FIG. 7 illustrates a modified configuration of the hook members for usein the apparatus of the invention.

The apparatus illustrated in FIG. 1 is especially suited for lifting alarge capacity drum 1, which preferably comprises a well known 44 gallondrum. Of course it could be dimensioned so as to be suitable with drumsof other sizes. It comprises a mobile frame 2 having a forward pair ofuprights 4 and a rear upright 6. The upper ends of the uprights arejointed by a generally U-shaped top support bar 8. The lower ends of thelegs are interconnected by lower braces 10. The lower ends of theforward legs 4 are provided with fixed axis wheels 12 whereas the rearupright 6 is provided with a swivel mounted wheel 14.

The device includes a pair of opposed hook members 16 which aresuspended from plates 18 which in turn are pivotally connected to theforward portions of the top bar 8. The plates 18 are interconnected by agenerally U-shaped handle 20 which also serves as a lever to effectrotation of the plates 18 and consequential elevation of the hookmembers 16. In FIG. 1 the handle 20 is in an upright position in whichit located in a plane inclined slightly forwardly relative to thevertical, it being stable in that position by engagement of the ends ofthe handle with the top support bar 8 as shown.

FIGS. 3 to 5 illustrate in more detail the preferred configuration ofthe plates 18 and hook members 16.

Referring firstly to FIG. 3 it will be seen that the plates 18 arepivotally connected to the bar 8 by means of threaded studs 23. The hookmembers 16 are mounted on the end of shafts 24 which are welded to theplates 18. The shafts 24 have reduced diameter portions 26 which extendthrough bores 28 in the hook members 16, the bores 28 being of largerdiameter than the portions 26 so as to permit limited rotation of thehook members in the axial direction of the shafts 24.

Rotation of the hook members 16 about the reduced shaft portions 26 islimited by means of struts 30 one end of each of which passes through arespective boss 32 located at the bottom of the hook members 16. Theother ends of the struts 30 passes through bores in a guide plates 34welded to the bar 8, the free ends terminating in a heads 36, as seen inFIG. 3. The bores in the plates 34 are somewhat larger than the diameterof the struts 30, the arrangement being such that there is approximately1 cm. of axial movement available to the struts 30 at any position ofthe handle 20 and this effectively limits the degree of rotation of thehook members 16. Washers 38 can be fixed on the struts 30 adjacent tothe hook members 16 so as to limit movement of the struts 30 through thebosses 32.

The mode of operation of the device will now be described. The framework2 with its handle 20 in the upright position as shown in FIG. 1 iswheeled towards a drum 1 which is standing in an upright position. Theframework 2 is wheeled about the drum until the lower side walls of thedrum engage the braces 10 at points of contact 36, as seen in FIG. 6. Atthis stage, the lower parts of the hooks 16 will be engaged by the upperside walls of the drum and will be restrained from rotating rearwardly(i.e. toward the upright 6) by the struts 30, as described previously.The handle 20 is now rotated from the position shown in FIG. 1 to thatin shown in FIG. 6. Rotation of the handle 20 causes rotation of theplates 18 and this has the effect of moving the hooks 16 upwardly andrearwardly as shown in FIG. 1A, the initial position of one of the hooks16 being shown in broken lines. The hooks 16 will move upwardly over thecurved surface of the drum 1 to a point a which they will engage the topseam 22 of the drum, as illustrated in FIG. 2. Once this engagementoccurs, further rotation of the handle 20 will cause the drum to beelevated and tilted slightly rearwardly towards the rear upright 6, asseen in FIG. 6. The tilting is caused by the rearward movement of thehooks 16. In the carrying position as shown in FIG. 6, the drum 1 issecurely engaged by the hook members 16 acting on its top seam 22 and isfirmly wedged between the braces 10 near its lower portions. The secureattachment of the drum 1 to the device when the drum is in its elevatedposition is particularly important since when the drum is beingtransported any bumps or uneven surfaces will not cause relativemovement between drum and the device. This is particularly importantwhere the drum 1 is heavy and/or contains toxic substances.

As will be apparent from FIGS. 1, 1A, and 6, the entire weight of thedrum 1 is borne by the device once the handle 20 is in its downwardposition. This is accomplished by the rearward movement of the hookmember 16 from the position shown in broken lines in FIG. 1A where it isforward of the axis of the screws 23 to the position shown in full linesin FIG. 1A where it is rearwardly of the axis of the screws 23. In thatposition, the handle 20 bears against the upper part of the support bar8, as best seen in FIG. 5. In other words the arrangement functions asan over-centre device whereby the weight of the drum 1 is borne by thedevice. The over-centre effect is made further secure by arranging forthe side parts of the support bar 8 to slope somewhat downwardly towardsthe rear upright 6, as shown in FIGS. 1A and 6.

FIG. 7 shows a slightly modified form of hook 16. In this arrangement,the hook is provided with two bores 28 one beneath the other so as topermit adjustment in the height of the hook 16 so as to accommodatevariations in drum sizes.

Many further modifications will be apparent to those skilled in the artwithout departing from spirit and scope of the invention.

We claim:
 1. A device for lifting an article, said device comprising:(a)a mobile frame (2) having two forward uprights (4) connected at theirupper ends by an upper support bar (8) and at their lower ends by alower support bar (10), said support bars being generally U-shaped sothat said two forward uprights define an open face adapted in use toreceive the article; (b) a pair of engagement members adapted to engagethe article to be lifted; (c) an actuator (18) having a U-shaped handle(20), the actuator being pivotally connected to said upper support barof the frame about a first axis located near said forward uprights, saidengagement members being connected to said actuator for pivotal movementrelative thereto about a second axis, said actuator being rotatable bythe handle between a first position where the article is not engaged anda second position where the article is in use engaged in which, in thefirst position, said engagement members are at a first level relative tothe frame and said second axis is located at a first lateral positionrelative to said first axis, and, in the second position, saidengagement members are at a second level, vertically higher than saidfirst level, relative to the frame and said second axis is located at asecond lateral position relative to said first axis, said second lateralposition being on the opposite side of said second axis to said firstlateral position, said handle extending in a generally upright plane inthe first position and a generally horizontal plane in the secondposition; and (d) abutment means (8) to restrain movement of saidactuator beyond its second position, and wherein in use, an article issupported by said engagement members and the weight thereof tends torotate said actuator into engagement with said abutment means.
 2. Adevice as claimed in claim 1 wherein the free ends of said U-shapedhandle are fixedly connected to actuating plates (18) which arepivotally connected to said upper supports bar at said first axis and towhich said engagement members are pivotally connected.
 3. A device asclaimed in claim 2 wherein the handle is held stable in its firstposition by abutment of the free ends of said U-shaped handle with saidupper support bar.
 4. A device as claimed in claim 2 wherein thearrangement of the handle, actuator plates and engagement members issuch that the handle functions as a lever with a substantial mechanicaladvantage.
 5. A device as claimed in claim 4 wherein said mechanicaladvantage is approximately 10:1.
 6. A device as claimed in claim 1wherein said engagement members comprise hooks.
 7. A device as claimedin claim 6 wherein said hooks are mounted upon shafts (24) which extendfrom said actuating plates for rotation about said second axis, themounting being such as to permit limited rotation about third axes whichare transverse relative to the said shafts.
 8. A device as claimed inclaim 1 including restraining means (30, 34) to limit rotationalmovement of said engagement members about said second axis.
 9. A devicefor lifting a drum (1) having a top seam (22) said device comprising: amobile frame (2); an upper support bar (8); a pair of inwardly facinghook members (16) which, in use, engage the top seam of the drum to belifted; a generally U-shaped handle actuator (18, 20) which is pivotallyconnected to said upper support bar about a first axis, said hookmembers being connected to said actuator for pivotal movement relativethereto about a second axis, said actuator being rotatable between firstand second positions in which, in the first position, said actuatorextends in a generally upright plane and said hook members are at afirst level relative to the frame and said second axis is located at afirst lateral position relative to said first axis, and, in the secondposition, said actuator extends in a generally horizontal plane and saidhook members are at a second level, vertically higher than said firstlevel, relative to the frame and said second axis is located at a secondlateral position relative to said first axis, said second lateralposition being on the opposite side of said second axis to said firstlateral position; abutment means (8) to restrain movement of saidactuator beyond its second position and wherein said hooks are mountedfor rotation about said second axis upon shafts (24) which extend fromsaid actuator, the mounting being such as to permit limited rotationabout third axes which are transverse relative to the said shafts; alower support bar (10) which is, in use, engaged by the sidewall of thedrum when the actuator is in its second position; two forward uprights(4) connected near their lower ends by said lower support bar and attheir upper ends by said upper support bar and near said first axis,said support bars being generally U-shaped whereby said two forwarduprights define an open face of the frame into which, in use, the drumis moved; and wherein, in use, the drum is supported by said hookmembers and the weight thereof tends to rotate said actuator intoengagement with said abutment means and to rotate said hook membersabout said third axis for more positive engagement thereof with the topseam of the drum.
 10. A device as claimed in claim 9 wherein the freeends of said U-shaped handle are fixedly connected to actuating plates(18) which are pivotally connected to said upper support bars at saidfirst axis and to which said hook members are pivotally connected.
 11. Adevice as claimed in claim 10 wherein the handle is held stable in itsfirst position by abutment of the free ends of the U-shaped handle withsaid upper support bar.
 12. A device as claimed in claim 11 wherein thearrangement of the handle, actuator plates and hook members is such thatthe handle functions as a lever with a substantial mechanical advantage.13. A device as claimed in claim 12 wherein said mechanical advantage isapproximately 10:1.
 14. A device as claimed in claim 9 includingrestraining means (30, 34) to limit rotational movement of said hookmembers about said second axis.